Do You Need a New Fuse Board for Solar Panels, a Battery or an EV Charger?

It's one of the first things an installer looks at when you ask about solar panels, a home battery or an EV charger: the fuse board. Sometimes it can take the new circuit as it is; sometimes it needs replacing first. Here's how to tell, and what the separate "main fuse" question is about. For prices and what's included, see our fuse board upgrade page.

Why new technology needs the board's attention

An EV charger, a solar inverter and a home battery each need their own dedicated circuit, protected at the consumer unit. So the board needs a spare way to connect it and protection suited to the new circuit. Every new circuit is also notifiable work under Part P, so it has to be tested and certified.

When your existing board is probably fine

• It's a modern metal-clad consumer unit with RCD or RCBO protection.
• It has spare ways for the new circuit.
• Testing shows the existing circuits are in good condition.

In that case the new circuit can usually be added without replacing anything, and a good installer won't push you into a new board.

When it probably needs replacing first

• It still has **rewirable fuses** or old cartridge fuses.
• There's **no RCD protection**.
• It has a **plastic casing** and dates from before the change to non-combustible enclosures.
• It's **full**, with no spare ways.
• Testing turns up faults the new circuit would make worse.

A new board is then the sensible first step, and it is far easier to do it before the new equipment arrives than to patch around an old board afterwards.

The main fuse: a different job, usually free

The main fuse sits in the sealed cut-out where the supply cable enters your home, and it belongs to your network operator, not you. Across South Yorkshire that's Northern Powergrid, which says that when you need more capacity for an EV charger, a fuse upgrade is in most cases a service it provides free of charge. Since July 2023 its standard domestic fuse has been 80A. Its standard design rules allow one EV charger and one heat pump on a domestic connection, and a looped supply shared with a neighbour has to be assessed first, which can mean a new service cable.

The installer handles this as part of the job: EV chargers must be notified to the network operator, and solar panels and batteries connect under G98 (notified within 28 days of commissioning) or, for larger systems above 3.68kW per phase, G99 approval before connection.

What it costs

Our fuse board upgrades typically cost £450–£650 for a standard board and £650–£950 for an RCBO board, including testing and certification. If you're having solar, a battery or a charger fitted at the same time, doing the board in the same visit saves a separate day of disruption.

The order that works

1. Test the existing installation. 2. Upgrade the board if it needs it. 3. Check the main fuse and supply with Northern Powergrid. 4. Add the new circuit and equipment, and certify the lot.

If you're in Doncaster or South Yorkshire and planning solar, a battery or a charger, we can look at the board, the supply and the new equipment in one survey — see our fuse board upgrade page or call 0333 577 5464.